Can Soy Cause Breast Cancer?

Research consistently shows that soy-based foods do not increase cancer risk

Does soy cause breast cancer? Given the increased interest in soy-based food and drinks, it’s safe to say that a lot of people want an answer to that question.

So, let’s get right to the point: Eating soy DOES NOT increase your risk for breast cancer. In fact, there’s plenty of research that suggests soy may offer some protection against getting the disease.

But rumors about soy and breast cancer continue to linger — and in truth, there are study-based explanations behind the misinformation.

Confused? Well, we don’t want that. So, let’s break down what the research shows and means to you with the help of two breast cancer specialists, oncologists Erin Roesch, MD, and Tiffany Onger, MD.

Why is soy linked to breast cancer?

Soy products contain isoflavones, molecules similar to the hormone estrogen. That has led to theoretical concerns that soy could increase the risk of estrogen-sensitive cancers, including breast cancer.

Receptors (protein molecules) on breast cancer cells can attach to estrogen in your system and fuel the growth of cancer. That’s one reason higher levels of estrogen increase breast cancer risk.

But while isoflavones resemble estrogen, they don’t make the same bond with those receptors to serve as a catalyst for cancer cell growth. “That’s a big distinction,” says Dr. Roesch.

Clinical trials consistently show that the intake of isoflavone​ does not adversely affect the risk of breast cancer. These studies haven’t confirmed a link between eating natural soy and developing breast cancer.

Some research even goes a step further by suggesting soy provides a protective effect.

So, what causes concerns about soy?

Research looking at soy and cancer risk shows little reason for concern when it comes to studies involving people. But when the